Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Cocero Nanette 2. Issuer Name and Ticker or Trading Symbol HilleVax, Inc. [HLVX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O HILLEVAX, INC., 321 HARRISON AVE, SUITE 500 3. Date of Earliest Transaction (Month/Day/Year) 09/17/2025 (Street) BOSTON, MA 02118 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 09/17/2025 U 17,199 D (1)(2) 0 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Cocero Nanette C/O HILLEVAX, INC. 321 HARRISON AVE, SUITE 500 BOSTON, MA 02118	X

Signatures

/s/ Paul Bavier, Attorney-in-Fact for Nanette Cocero		09/17/2025
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	In connection with that certain Agreement and Plan of Merger, dated as of August 4, 2025 (the "Merger Agreement"), by and among the Issuer, XOMA Royalty Corporation ("Parent") and XRA 4 Corp., a wholly owned subsidiary of Parent ("Merger Sub" and together with Parent, the "Purchasers"), the Purchasers completed a tender offer to acquire all of the issued and outstanding shares of Common Stock of the Issuer in exchange for (a) $1.95 in cash per share (the "Cash Amount"), plus (b) one contingent value right ("CVR") representing the right to receive certain contingent cash payments equal to the "CVR Proceeds" as further described in that certain CVR Agreement entered into between the Purchasers and a representative to the CVR holders. After completion of the tender offer, Merger Sub merged with and into the Issuer, effective as of September 17, 2025 (the "Effective Time"), with the Issuer continuing as the surviving corporation and as a wholly owned subsidiary of Parent.
(2)	Pursuant to the terms of the Merger Agreement, immediately prior to the Effective Time, each outstanding restricted stock unit ("RSU") immediately vested in full and was canceled in exchange for the right to receive (a) an amount in cash, without interest, equal to the product obtained by multiplying (x) the Cash Amount by (y) the number of shares underlying such RSU at the Effective Time and (b) one CVR for each share underlying such RSU.

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